Chandelier lamps are very popular in homes and commercial places for decorative effects. An example of two chandelier lamps are shown as prior art in FIGS. 1 and 8 as reference letters A and B. Conventional chandelier lamps are traditionally hung from a ceiling or the like and use special shaped tungsten light bulbs with some cylindrical shaped stands below to mimic the candle lights. The tungsten filament inside the bulb is in a shape to mimic the flame of a candle light. With the glass crystals around, the modern chandelier lamps can create the same sparkling and romantic feelings of the beautiful candle lights in royal palaces and luxury homes for centuries.
Chandelier light bulbs are mostly available in 25 Watts and 40 Watts. Typical luminous efficiency is less than 15 Lumens per Watt. By today's standard, these are extremely inefficient light bulbs. That makes the chandelier lamps the most inefficient light fixtures in use today. However, they provide the unique decorative effects that can not be matched by any other light fixtures. This makes the chandelier lamps very popular all around the world.
In order to improve the energy efficiency of the chandelier lamps, a new chandelier light bulb based on compact fluorescent lamp technology was introduced to the market recently. A picture of this fluorescent prior art chandelier light bulb C is shown in FIG. 2.
In 2009, the European Union banned the commercial sales of tungsten filament light bulbs. That makes the compact fluorescent chandelier light bulb the only widely available alternative to replace the traditional chandelier bulbs. Other countries will likely follow suit. However, the fluorescent chandelier light bulbs do not provide the unique features of the traditional chandelier light bulbs.
First, the bulb has a wide spiral shaped fluorescent tube inside. As a result, the bulb requires a plastic envelop that is significantly larger than the traditional chandelier light bulbs. Second, in order to hide the spiral fluorescent tube, the molded plastic envelope has a flossy finish. This finish is very detrimental and does not give the sparkling feeling of the tungsten chandelier light bulb. Third, most of these fluorescent chandelier light bulbs run at 4 Watts. Even with the high efficiency of the fluorescent lamps, it emits only 195 Lumens. This is significantly less than the 300-600 Lumens emitted by the traditional tungsten chandelier light bulbs. Therefore, the light can appear to be dim to people used to using the prior bulbs and it is difficult to add bulbs to a lamp. Fourth, it is difficult to dim the fluorescent lamps to create the romantic and traditional decorative effect. With these issues, the fluorescent chandelier light bulb, even it is 400% more energy efficient, is not a good replacement of the tungsten chandelier light bulbs.
The light generating efficiency of LEDs commonly exceeds 60 Lumens/Watt. This is even more efficient than the compact fluorescent light bulbs. With LEDs, it is easy to have chandelier light bulbs that are 4 to 5 times more efficient than the tungsten filament chandelier light bulbs.
Currently, there is no large commercial distribution of chandelier light bulbs using light emitting diodes “LEDs”. The fundamental reason is perhaps that an LED light bulb with 300-600 Lumens light output is still very expensive today. Also, in order to replace the tungsten chandelier light bulb, the LED light bulb has to run on AC voltage available at home. Therefore, it requires a special driving circuit inside each light bulb.